Their approach - laying out all of the abstract categories first - is (as Molly puts it) excellent as explaination, but wholly inadequate as education.

This is typical of the structure of formal education, but it's like trying to teach a baby to speak by first laying out grammar!

In the real world, quick returns are essential for successful pedagogy. Every goo and ga (with appropriate support and encouragement) is a source of satisfaction; every cry is answered. Without continual re-enforcement, it's impossible to keep moving forward.

In this light, how does our formal educational system function at all? By adding re-enforcemnt which is entirely extrinsic to the process - the "test." It works. The test provides an quick-turnaround motivational mechanism. That the social reward/punishment is extrisic to the power of the material itself is secondary. It works. That is the first thing.

The consequences could be traced out and the reasons discussed. Highlighting two: a) it's a good preparation for work-type reward/punishment sockets; b) it alienates students from their growing power.